Manual sharpening steels have been used for years with the belief that they are a means of straightening the burr from knife edges following the sharpening of edges with manual or powered abrasive stones. Butchers have found the manual sharpening steel to be useful when slaughtering or butchering in work areas removed from electrical power and running water. The exact nature of what can occur during the steeling process has been until recently the subject of extensive speculation with little understanding of mechanisms that can occur at the edge of a blade as it is being impacted under controlled precisely repetitive conditions against a sharpening steel.
Use of the manual steel rod has been more of a mystique than a science, lacking any scientific base or understanding. It has been said for example that the manual rods “smooth out microscopic nicks in the blades surface and realigns the molecules in the cutting edge”. Also one reads that “the best steels are magnetized to help draw the molecules into realignment,” or “the alignment of molecules in a knife blade are reinforced whenever it is sharpened, . . . and the process removes very little actual metal from the blade”. Others repeat that the use of a steel “realigns and smoothes the knife's edge”. Most often, it is thought that the steel “burnishes against the hard surface of the cutting edge for the purpose of straightening it back out so that it is the same way as when it was manufactured”.
Clearly steeling of knife blades has been a poorly understood art and not a science. It is clear to those founded in science and physics that the force of magnetism incorporated in some commercial sharpening rods is far too feeble to have any effect at the atomic level in steel and even too feeble to alter the physical structure of any burr attached to the edge.
In the prior art the angle of the facet as presented to the hardened surface of the manual sharpening steel has been totally random and entirely dependent on operator skill. For this reason, prior means of steeling knife edges lack the precision and reproducibility discovered by these inventors to be necessary for creating an optimum consistent physical structure along the cutting edge of blades irrespective of the geometry and size of the blade geometry or the skill of the user.
While manual sharpening steels have been sold for many years they have not become popular with the general public because they are dangerous to use and a very high degree of skill and practice is required to realize any improvement in the cutting ability of a dull knife edge.